fire lapping grits

[Marine Sgt 2111]

does anyone know for sure, what grades of grit are used in lapping compound to fire lap barrels?

[725]

I've used 800 grit on several occcasions & have been very satisfied. Go slow and clean it alot during the process. Stop before you think it's completely done. Clean, clean, clean the grit out. My buddy had a brand new Rem .308 heavy barrel and it shot very poorly. A tight oiled patch ran through the barrel easily enough but you could feel restrictions at at least one place within. Bedded the action, floated the barrel - no joy. As a last resort, I fire lapped it. Outstanding. I'm sure there is a proper way to do it, but I just took some FMJ surpuls and rolled the grit in the body of the bullet. It works if that's your problem. Now I carry two metal flat plates in my range bag and some "Flitz" The plates ar about 3/4 of an inch x 3 or 4 inches. Just enough for the loaded cartridge's bullet to be rolled back and forth to immbed the grit. Good luck.

[Marine Sgt 2111]

I have the same set of plates that I made 25 years ago to roll lead bullets on and inpregnate them with lapping compound. The reason that you should use lapping compound vs diamond compound is that diamond compound is for hardened surfaces and gets imbedded into the surface of the metal. Oil or water based compounds do not imbed and clean out easily.

Crocus(sp) cloth is usually 600 grit so it will be a good grit to start with and go up from there.

I will head down to the local machine tool supply house and pick up small containers of the various grits and keep you posted of the results.

[TC66]

I use lead cast bullets. I start with 600 grit and then finish with 800 grit.

[Marine Sgt 2111]

Thanks TC66 for the input...